amino acid

noun

: an amphoteric organic acid containing the amino group NH2
especially : any of the various amino acids having the amino group in the alpha position that are the chief components of proteins and are synthesized by living cells or are obtained as essential components of the diet

Examples of amino acid in a Sentence

Recent Examples on the Web
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Diving deeper, the researchers found that the reason the western plants were pumping out an ancient mix of alkaloids had to do with a change to four amino acids in one of the plants' enzymes. New Atlas, 29 June 2025 Taurine is an abundant amino acid and a key ingredient in energy drinks like Red Bull. Tom Chivers, semafor.com, 10 June 2025 When protein is properly digested, it’s converted into amino acids and peptides, whereas undigested proteins can alter the intestinal environment. Misaki Kawatsu, Vogue, 10 June 2025 Fueled by social media, more boys and men are turning to supplements like amino acids, creatine monohydrate, pre-workout drinks or powders, protein bars and whey protein product in an effort to bulk up and look like their cartoon superhero. Scott Lafee, San Diego Union-Tribune, 3 June 2025 See All Example Sentences for amino acid

Word History

First Known Use

1897, in the meaning defined above

Time Traveler
The first known use of amino acid was in 1897

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Cite this Entry

“Amino acid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amino%20acid. Accessed 6 Jul. 2025.

Kids Definition

amino acid

noun
ami·​no acid
ə-ˈmē-nō-
: any of numerous acids that include some which are the building blocks of proteins and are made by living cells from simpler compounds or are obtained in the diet

Medical Definition

amino acid

noun
: an amphoteric organic acid containing the amino group NH2
especially : alpha-amino acid

More from Merriam-Webster on amino acid

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